1. Field of the Invention
The present invention relates to an optical engine of a projection system and a fabricating method thereof, and more particularly, to an optical engine of a projection system which can prevent non-matching of red, green, and blue color images by reinforcing the intensity of the optical engine of the projection system and a fabricating method thereof. More specifically, it relates to the an optical engine of a projection system which can improve the reliability of image matching by preventing a composition unit from moving by external force, and furthermore a relative position of a LCOS panel and a position of a quad and the like from moving through intercepting transmission of external force to a composition unit, and a fabricating method of the optical engine.
2. Description of the Background Art
Unlike a general liquid crystal display, a liquid crystal on silicon (hereinafter, referred to as “LCOS”) that is a kind of a reflecting-type liquid crystal display forms a liquid crystal cell on a semiconductor substrate and can realize a high definition of a XGA grade or more in a small size of about one inch by arranging switching circuits and elements of each pixel in high integration.
For these reasons, the LCOS panel has been attracted as a display device of the projection system and technical development and commercialization of the LCOS panel and a projection display system using the LCOS panel have been actively progressed.
In order to embody a full color screen, the LCOS projection system uses a three panel type which converts white color light to RGB three color light, has three LCOS panels corresponding to the R, G, B light to compose R, G, B images embodied by each LCOS panel in a color image, and projects the composed image to a screen.
Such general LCOS projection system includes an illumination unit for projecting light, a composition unit for composing RGB three images displayed in the LCOS panel in an image after projecting light, a projecting lens for projecting light composed in the composition unit, and a screen for displaying light projected from the projecting lens to an image. Three LCOS panels are additionally fixed to the composition unit, after each of RGB three color light separated from white color light is incident to the LCOS panel, it is reflected and the reflected light is composed. A quarter-wave plate is provided in a neighboring position of the LCOS panel to improve a contrast of an image. The quarter-wave plate performs an operation converting linear polarized light to circular polarized light.
On the other hand, three LCOS panels are provided to compose RGB color light. In a case where the panel is a three panel type as described above, it is important that image matching between the respective LCOS panels is accurately performed. It is also important that image matching between the quater-wave plate and the LCOS panel is accurately performed.
In order to accurately perform the image matching, when the quad housing which is a single body and to which three color quads are attached to is provided, the LCOS panel assembly forming the quater-wave plate and the LCOS panel as a one piece are fastened to the quad housing. Thereafter, the LCOS panel assembly operates to adjust image matching.
Although the image matching is performed at a state where the LCOS panel assembly is coupled to the quad housing, there is a problem in that non-matching of an image may be generated when the quad housing is deformed during a process of coupling the quad housing to the optical engine. Therefore, there is a disadvantage in that an operator should perform the image matching once again, and this operation becomes an important problem in a manufacturing site. This problem may be also generated even when external shock is applied to the optical engine after manufacturing of the optical engine is completed.
Further, although the composition unit including the quad housing is made of a strong material, a shape of the composition unit and a coupled relation between parts may be deformed by continuous external force, and this problem frequently occurs as using time of the projection system is long. Therefore, as a use period of the projection system is prolonged, non-matching of an image is generated, whereby image quality is deteriorated or the durability of the projection system is deteriorated.